The relative error (32), for Gaussian and exponentially correlated noises, as a function of Omega _s^{(0)}/Gamma _2, for various bandwidths of the field

2013-08-13T00:00:00Z (GMT) by G M Nikolopoulos P Lambropoulos

Figure 5. The relative error (32), for Gaussian and exponentially correlated noises, as a function of \Omega _s^{(0)}/\Gamma _2, for various bandwidths of the field. (a) γ = 6.67Γ2; (b) γ = 3.33Γ2; (c) γ = 1.67Γ2; (d) γ = 1.11Γ2. Other parameters: Gaussian pulse profile, Γ2τ = 3, 5000 random pulses, Δs = 0, t = t0.

Abstract

Motivated by recent experiments pertaining to the interaction of weak SASE-free-electron-laser (FEL) pulses with atoms and molecules, we investigate the conditions under which such interactions can be described in the framework of a simple phase-diffusion model with decorrelated atom–field dynamics. The nature of the fluctuations that are inevitably present in SASE-FEL pulses is shown to play a pivotal role in the success of the decorrelation. Our analysis is performed in connection with specific recent experimental results from FLASH in the soft x-ray regime.